In Japanese Patent Application No. 48-122461 (published under No. 57-17682) the applicant has proposed an apparatus for cutting opposed irregularly shaped ends of veneers and bonding the veneers together at their flat end faces formed by the cutting of the irregularly shaped ends. In this apparatus a veneer is conveyed onto a main roller, and its opposed irregularly shaped ends are cut to produce opposed flat end faces. Then, the veneer is conveyed onto a veneer supporting member provided for pivotal movement. The rear end portion of the veneer on the veneer supporting member is lightly pressed by a pressing roller provided in conjunction with the veneer supporting member. Thereupon, the rear end of the veneer on the veneer supporting member is raised to a middle position. Then, a front irregularly shaped end of a second veneer is conveyed beneath the cutter. At the same time the rear end of the preceding veneer on the veneer supporting member is raised to a highest position adjacent an adhesive material applying roller on which a thermoplastic adhesive material is applied in advance. When it reaches the highest position, the upper surface of the veneer is coated with the adhesive material from the adhesive-material applying roller. The adhesive material is thus applied to the upper surface of the rear end portion of the preceding veneer. Then, the front irregularly shaped end of the second veneer is cut to produce a flat front end face. Thereupon, the rear end of the preceding veneer is lowered to bring the flat rear end face of the preceding veneer into contact with the flat front end face of the second veneer. Thereupon, the main roller is restarted to move the two veneers forward. Thus, the adhesive material on the upper surface of the rear end portion of the preceding veneer is spread on to the upper surface of the front end portion of the second veneer by the pressing roller. The adhesive material thus is also applied to the upper surface of the front end portion of the second veneer to bond the two veneers together. Then, a rear irregularly shaped end of the second veneer is also cut to prepare to bond the second veneer to a third veneer.
A principal drawback of the foregoing apparatus is that the adhesive material is applied not to the flat rear end face of the first veneer or the flat front end face of the second veneer, but to the upper surfaces of the rear end portion of the first veneer and of the front end portion of the second veneer. Therefore, the bond between the veneers is not very strong. In particular, the thicker the veneers, the weaker the bond. Another drawback is that the position where the veneers are brought into contact with each other is rather distant from the position where the adhesive material (a thermoplastic adhesive) has been applied to the first veneer and, hence, the adhesive material applied to the first veneer may start to set, due to natural cooling, before the first veneer contacts the second veneer. If setting occurs early, the first veneer does not adhere well to the second veneer.
The inventors are also aware of Japanese Patent Application No. 49-119757 (published under No. 51-46498) which discloses a similar apparatus to the one described above. In this apparatus a veneer is conveyed beneath a cutter, and its opposed irregularly shaped ends are cut to produce opposed flat end faces. The veneer is received on a veneer supporting member. Thereupon, the rear end of the veneer is raised to a position close to a pivotable adhesive-material applicator. Then, the applicator is pivoted to apply an adhesive material to the flat rear end face of the veneer. Thereupon, a second veneer is conveyed, and its front irregularly shaped end is cut to produce a flat front end face. Then, the rear end of the preceding veneer is lowered to bring the flat rear end face of the preceding veneer into contact with the flat front end face of the second veneer. The two veneers are thus bonded.
A major difference between the first and second apparatus is that in the first apparatus the adhesive material is applied to the upper surface of the rear end portion of the first veneer and the upper surface of the front end portion of the second veneer, whereas in the second apparatus the adhesive material is applied to the flat rear end face of the first veneer. However, with the second apparatus, much of the adhesive material applied to the flat rear end face of the first veneer is quite likely to be removed when it contacts the front upper edge of the second veneer when the flat rear end face of the first veneer is lowered to contact the flat front end face of the second veneer. This is because the flat end faces of the veneer are "straight", or are at right angles to the upper and lower surfaces thereof. This is a major drawback of the second apparatus. In addition, the second apparatus has the same drawback as the first apparatus, i.e., that the position where the veneers are brought into contact with each other is rather distant from the position where the adhesive material has been applied to the first veneer. Another drawback of the second apparatus is that the adhesive-material applicator is not fixed, but is turned when an adhesive material is to be applied to the veneer. It makes the entire apparatus rather complex.